How to create a vertex group?
Create a Vertex group

Select the faces or edges or verts

In my example i have selected faces

Press Ctrl+G a pop-up (click on assign group)



If u have multiple group and when u click Ctrl+G 



Select the group to which u want to assign in the vertex 



To check the vertex you have made. Deselect all the faces or edges or verts. And in the vertex panel. Select the vertex group and below press select. And it select all the faces or edges or verts assign in that group